I use a Remington 870, over a semi-auto as the same theory applies with a pump as with a bolt action rifle. The energy from the shell is not being used to work the action, so it expends more of that shell energy out the front of the barrel. The choke that i use is not for everyone, as some hunters do not want to spend the $90 that this guy gets, but he guarantees it will outperform any other choke on the market, and it does. The shells I use are custom loaded, in 3.5". I have shot this load at 30 yards at a standard Quaker Boy Target, and had 240 pellets in the neck/ head region, not the 10" circle but actually in the neck and head, at 40 yards 125 pellets, at 50 yards, 82 pellets, at 60 yards 93 pellets and at 70 yards 63 pellets. I have had several people state that the load they use kills them dead and dead is dead, so what's the difference. The difference is, more pellets allows you additional room for error, especially if you have no holes in that pattern,and I know I still get excited, so I can pull off slightly or whatever we do when in the heat of the moment.
I also want to add that I don't condone shooting birds out far, and prefer to call them in close as mentioned, BUT, I also like the option of being able to kill that bird, as mentioned above, if he is hung up and just won't come in and thinks he is safe. Especially on a trip that I have traveled some distance and spent considerably more than just hunting around home. You can view the targets at
www.farleysadventures.com